Well cementing apparatus



June 9, 1942. c. w. THORNHILL 2,286,126

4 WELL CEMENTING APPARATUS Filed July 5, 1940 Patented June 9, 1942 WELL CEMENTING APPARATUS Charles W. Thornhill, Houston, Tex. Application July 5, 1940, Serial No. 343,925

Claims.

' This invention relates to float collar, guide shoe and cementing tool combinations and more particularly to those for use on the lower end or at spaced points above the lowerend of an oil well casing for use in the cementing operation. This invention constitutes an improvement over the inventions disclosed in my previous copending applications S. N. 107,770 filed October 27, 1936 now Patent No. 2,212,086 issued August 20, 1940; S; N. 306,225 filed November 27, 1939 now Patent No. 2,212,087 issued Aug. 20, 1940, and S. N. 330,487 filed April 19, 1940. I

7 It is a general object of this invention to provide certain improvements in the structure and operation of the devices shown and claimed in my prior pending applications referred to.

Another object of this invention is to provide a device which may be more easily and quickly assembled.

' Another object of this invention is to provide a device of the character referred to, the parts of which may be more cheaply produced than those disclosed in my prior applications.

Another object of this invention is to provide a device in which the means for closing the slush passage will not be required to seat upon the means for closing the lateral cement openings.

Other objects and advantages of this invention will become apparent from the following description taken in connection with the accompanying drawing wherein like numerals represent corresponding parts throughout and wherein is set forth one embodimentof this invention.

In the drawing:

Fig. 1 is a vertical cross section through a device constructed in accordance with this invention, the same being illustrated as a guide shoe in this instance;

Fig. 2 is a view partly in elevation and partly in vertical cross section illustrating the check valve'retaining element forming a part of the device illustrated in Fig. 1;

Fig. 3' is a transverse cross section taken along the line 33 in Fig. 1.

As in the usual case, the lower end of the casing l is threaded to receive the cement shoe. In this instance that shoe consists of a collar 2 having a long internally threaded zone 3 at its upper end and a relatively short internally threaded zone 4 at its lower end. The lower edge of this collar is beveled as illustrated at 5 so as to form a bell-shaped end on the collar.

Threaded into the upper end of. the collar before it is placed on the casing I is a check valve seat member 6 having a passage 1 therethrough,

the upper end of which is flared as at 8 so as to guide any material passingdownwardly through the casing into the passage 1, and the lower end of which is provided with a flexible sealing ring 9 adapted to serve as a valve seat.

The outer surface of this seat element is I threaded as shown at Ill so that itmay be engaged with the threads 3, and atlts lower end this element is provided with a .short reduced externally threaded-part H to'which the valve retaining element 12 is secured. This valve retainingelement 12, as shown in Fig. 2, consists of an element internally threaded at 13 adjacent its upper end and having downwardly extending flanges It turned inwardly'at their lower edges as illustrated at 15. The ball check valve I5 is of such a size as to rest against these inwardly turned lower edges'll'o and be retained thereby.

The ball valve l6 should, of course, be put into 0 position before the valve seating element 6 is inserted intothe collar 2, and the retaining mem ber 12 should then be put in place on the element 6. The entire assembly may then be put into the proper position in the collar 2 with one operation.

Threadedly mounted in the lower end of the collar is the guiding element II. This element is externally threaded to engage the threads 4 in the collar 2 and is provided with a tapered shoulder to engage the flared surface 5 of the collar 2. Its lower end is rounded so as to provide a guide for the device.

The element 11 has a central passageway I8 therethrough in which is provided intermediate its ends an upwardly facing valve seat 19 adapted to receive a ballvalve 20.v Theside wall of this annular element is of U -shaped or channel shaped cross section having a hollowed out annular portion 21 therein open at its upper end. The upperend of the element-I1 is provided with a surface which is adapted to receive the frustoconical diaphragm 22, this diaphragm serving to initially close the upwardly open endof the hollowed out part 21. It is also provided with ribs 23, which would serve to support the ball [6 in the event it should in some manner escape from its retainer. Thus the ball l6 would be prevented from closing th opening through the element ll.

Theqdiaphragm 22 is made of a frusto-conical shape for the further reasonthat it will be able be made of any desired substance.

down solely by a hold-down ring 24 mounted within a circumferential channel in the collar 2, the diaphragm in that case being held against the ring 23 by the element I].

The diaphragm 22 may bemade of. such thickness that the pressure under which it will break can be accurately predetermined. It' may also be of a nature such that it will shatter when it breaks or it may be tough so that when it breaks it will remain in one piece and merely tearrsufficiently to permit the passage of fluid. In the event that it is of the nature that it will shatter, 1

the broken particles thereof will be caught in the lower portion of the hollow 2|.

Extending outwardly from the hollow 2| are} still other openings 25, which are adapted to sub-\ stantially register with corresponding openings" 16 in the collar 2. These openings and 26 may be formed by one drilling operation after the element I1 is in place in the collar 2.

ln operation, slush or other liquid may be pumped downwardly through this device as the .casing is being-"lowered 'into. the well because under such circumstancesthe ball 20 will notbe in .place and the' ball IE .will merely serve as a checkva'lve. I I T r Whena point has been reached at which it iszdesired tobegin the .cementingoperation, the

--ball 20:will be dropped in at the top of the welland the operation of pumping in the cement will be begun.'-- The ball 20. will passdownw'ardly' through. the passage I andpast the ball 16 and will .seat upon the seat 19, which has been deand 26 into the space about the collar2.:

.The cementing operation will thereupon be completed in the usual manner.

U It will readily be appreciated that the elements 6,-IT and 22. and ball valves I6 and 20 may Preferably, however, they will be made of some readily 'drillable substance so that after the cement has set it will be possibleto drill down through the the elements I] may be readily drilled-out without rotating within the collar 2.

It will be seen that by this invention there has been provided'a structure which may be much readily manufactured and assembled than those heretofore described and claimed in my co-pending applications. In the present instance, for example, it willbe seen that the element 6 may be molded in a much simplermold by virtue of the 'fact that'the retainer [2 is made separate from and is threadedly secured to the element 6. The retainer I2 is also of a nature which makes it very simple to mold.

The element I! can readily be molded and would require substantially no finishing because there are no close fitting parts. The diaphragm may take various shapes and may in some insure within'the collar2'rises toa'pred'etermined cumstances the present device can be operated" by'buildingwup suflicient pressure to break the diaphragm, even though no fluid can be pumped through the bottom of the casing, and the ce menting operation can thus be carried out, whereas this could not be done in the case of a device in which the cementing operation must be preceded by or accompaniedby a flow of fluid through the lower end of the shoe.

Havingdescribed my invention, I c an 1i: l. In' a casing shoe, in combination, apipe,

' a checkvalve in said pipe fonprventing up flow therethrough. said pipe having independent slush and cement openingstherein belowsa-id check valve; a. frangible closure element initially closing said cement opening and adapted to be fractured by excessive pressure within said-pipe, and

means independent of said first closure means for closing said slushfopening so'that excessive pressure may be built up to fracture said first closure means'and permit flow throughsaid cement opening.

2. In a casing shoe, in combination, a pipe, acheck valve in said pipe for preventing-upfiow therethrough, said'pipe having independent slush and cement openings therein below said check valve, a closure element initially closin'gfsaid ce'' ment opening and of a nature adaptedto be ruptured by a predetermined pressure within'sa'id pipe but being relatively tough so that it wil-l'not shatter upon being ruptured, and means indeslush opening so that excessive pressure sufli .cient to rupture first closing means may be builtup within said pipe. 1

3. In a well cementing device, in combination,

apipe, a'check valve.in.said pipe for preventing up flow therethrough, said pipe having indecalled a diaphragm, but the main essential is that such element be capable of preventing the flow of liquid into the hollow 4 until the prespendent slushand cement openings therein below said check valve, a frangible diaphragm initially closing said cement opening, and. means independent of said first closing means and movable downwardly past said check valve for 'closingsaid slush opening so that excessive pressure may be built up within said pipe to cause the rupture of said diaphragm. a

4. In a casing shoe, in combination, a pipe, a check valve in said pipe for preventing up'fiow therethrough, said pipe having independent slush and cement openings therein below said check valve, 9. frangible element initially closing said cement opening and of apredetermined strength so that it will break under a predetermined pressure within said pipe, and means independent of said first closing means and movabledownward- 1y past saidcheck valve for closing said slush,

opening so that such predetermined pressure may be built up to, rupture said: first closing means. o I

5. In a well cementing device, in combination, a pipe, a check valve in said pipe for preventing up flow therethrough, said pipe having an axial slush opening and circ'umferentially spaced lateral cement openings independent of each other below said check valve, an annular diaphragm initially closing said cement openings, and means independent of said annular diaphragm and,

movable downwardly past said check valve and through said annular diaphragm for closing said slush opening'so that an excessive pressure may be built up within said pipe to rupture said annular diaphragm.

6. In a device of the character described, an annular valve seat element having a central opening therethroughwith an upwardly facing valve seat therein, said element having an upwardly open recess and the upper surface of said element having a seat for an annular, frangible closure member to close the entrance to said recess, said element having parts on its outer surface for engagement with the inner wall of a pipe to hold said element in place in such pipe. and an opening'from the interior of said recess to the outside of said element.

7. In a device of the character describechan annular valve'seat element having a central opening therethrough with an upwardly facing valve seat therein, said element having an upwardly open recess and the upper surface of said element having a seat for an annular frangible closure member to close the entrance to said recess, and an opening from the interior of said recess to the outside of said element.

8. In a device of the character described, an annular valve seat element having a central opening therethrough with an upwardlyfacing valve seat therein, said element having an upwardly open recess and the upper surface of said element having a seat, an annular, frangible closure member to close the entrance to said recess seated upon and secured to said seat, and an opening from therinterior of said recess to the outside of said element. a

9. Ina device of the character described, an

annular valve seat element having a central opening therethrough with an upwardly facing valve seat therein, said element having an upwardly open recess and the upper surface of said element having a seat, an annular inverted frusto-conical frangible closure member seated upon said seat to close the entrance to said recess, and an opening from the interior of said recess to the outside of said element.

10. In a device of the character described, an annular valve seat element having a central opening therethrough with an upwardly facing valve seat therein, said element having an upwardly open recess and the upper surface of said element having a seat, an annular inverted frusto-conical closure member seated upon said seat to close the entrance to said recess, and means carried by said closure member adapted to receive a member substantially largerethan said valve seat and prevent the closure by such member of the passage through said closure member.

11. In a device of the character described, an annular valve seat element having a central opening therethrough with an upwardly facing valve seat therein, said element having-an upwardly open recess and the upper surface of said element having a seat, -an annular frangible closure member adapted to close the entrance to said recess and having an opening therethrough of a size sufficient to permit the passage of a valve to seat upon said valve seat, and an opening from the'interior of said recess to the outside of said element.

12. In a device of the character described, an annular valve seat element having a central opening therethrough with an upwardly facing valve seat therein, said element having an up wardly open recess and the upper surface of said element having a seat, an annular inverted frusto-conical closure member seated on said seat to close the entrance to said recess, the opening through said closure member being of a diameter sufficient to permit the passage of a valve to seat upon said valve seat, and an opening from the interior of said recess to the outside of said element.

-13. In a device of the character described, a

replaceable seat element for a, check valve, said element having a downwardly facing valve seat and a threaded exterior surface whereby it may be threadedly engaged with the interior of a pipe section, and having a reduced threaded extension on its lower end, a valve retaining element threadedly engaged withsaid extension, and a ball valve adapted to seat against said valve seat and freely movably entrapped by said valve retaining element.

, 14. In a casing shoe in combination, a pipe, said pipe having a central passage with a slush opening therefrom, a recess communicating with said central passage, and a plurality of cement" openings providing communication between said recess and the exterior of said pipe, a single frangible diaphragm initially closing ofi communication between said central passage and said recess, and means independent of said first closing means and movable downwardly past said first closing -means for closing said slush: opening so that excessive pressure may be built up within said pipe to cause the rupture of said diaphragm.

15. In a casing shoe in combination,' a pipe,

said pipe having a central passage with a; slush' opening therefrom, a recess communicating with said central passage, and a plurality of cement openings providing communication between said recess and the exterior of said pipe, frangible means initially closing off communication between said central passage and said recess and 1' adapted tobe fractured by excessive pressure within said pipe, and means independent of said first closure means and movable downwardly past said first closure means for closing said slush opening so that excessive pressure may be built up to fracture said first closure means and permit flow through said cement openings.

CHARLES W. THORNHILL. 

